KEV Intelligence

Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2020-3259

Cisco Adaptive Security Appliance (ASA) Software Information Disclosure

Cisco / Cisco Adaptive Security Appliance (ASA) Software · affected before 6.2.3.16

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Severity
CVSS 7.5 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
69.3%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2020-3259 is an unauthenticated vulnerability affecting Cisco Cisco Adaptive Security Appliance (ASA) Software. A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Cisco / Cisco Adaptive Security Appliance (ASA) Software affected before 6.2.3.16.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Cisco Adaptive Security Appliance (ASA) Software Information Disclosure

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to retrieve memory contents on an affected device, which could lead to the disclosure of confidential information. The vulnerability is due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. An attacker could exploit this vulnerability by sending a crafted GET request to the web services interface.

A successful exploit could allow the attacker to retrieve memory contents, which could lead to the disclosure of confidential information. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.

Vendor Product Affected Status
cisco firepower_threat_defense Before 6.2.3.16 Affected
cisco firepower_threat_defense Before 6.3.0.6 Affected
cisco firepower_threat_defense Before 6.4.0.9 Affected
cisco firepower_threat_defense Before 6.5.0.5 Affected
cisco adaptive_security_appliance_software Before 9.8.4.20 Affected
cisco adaptive_security_appliance_software Before 9.9.2..67 Affected
cisco adaptive_security_appliance_software Before 9.10.1.40 Affected
cisco adaptive_security_appliance_software Before 9.12.3.9 Affected
cisco adaptive_security_appliance_software Before 9.13.1.10 Affected
Cisco Cisco Adaptive Security Appliance (ASA) Software n/a Affected
View vendor advisory (opens in new tab)
Published
06 May 2020
Exploitation Reported
15 Feb 2024
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

edge malware nessus_scanner ransomware cisa

CVE References

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 15 Feb 2024

Independent exploitation attestation added to the KEV Intelligence record.

Used in malware

CISA

Recorded 15 Feb 2024

Malware families have been linked to exploitation of this CVE.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
CISA First 2024-02-15 00:00 UTC
CVE 2026-08-12 04:21 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
0
User-Agents
0

Raw values available in Pro and Enterprise.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nessus https://www.tenable.com/plugins/nessus/137659 02 Jun 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

69.3%

Weaknesses

Exposure of Sensitive Information to an Unauthorized Actor CWE-200

All CVSS Scores

CVSS v3.1 7.5 High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v3.0 7.5 High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v2.0 5.0 Medium

AV:N/AC:L/Au:N/C:P/I:N/A:N

Timeline

From disclosure to observed exploitation

  1. KEV confirmed by CVE

    Exploitation attested by an external source

  2. Nessus plugin available

    Scanner coverage available

  3. Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. First public exploitation report

    Exploit observed in malware

  5. CVE published

    Vulnerability disclosed publicly

  6. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2020-3259

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2020-3259",
  "confidence": "Confirmed",
  "cvss_score": 7.5,
  "cvss_estimated": false,
  "epss_score": 0.69336,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

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